Argentina Midterms to Offer Signal for Kirchner Successor

MAR DEL PLATA, Argentina—The important question heading into Argentina's midterm elections isn't whether the ruling Peronist movement will win, but which of its dueling factions will gain the upper hand in the run-up to presidential elections in 2015.

A third of the Senate and half of the Lower House are in play on Sunday. The Victory Front's majority in the house looked safe against a divided opposition, though its slim majority in...